Prof. T. G. Bonney—The Chalk Bhiff at Trimingham. 401 



if admitted tliey do not substantiate bis conclusions. So T leave 

 tbem and the nomenclature of zones to experts like Messrs. Jukes- 

 Browne ^ and A. W. Rowe, and restrict myself to such as bear on the 

 question discussed in our former paper, which dealt almost ex- 

 clusively with the so-called northern block or blocks near 

 Trimingham.^ Mr. Brydone maintains the most noted one to be the 

 remnant of a sea-stack or buried cliff, adopting a modification of the 

 view put forwai'd by Mr. Jukes-Browne.^ This stack or cliff was 

 formed at the margin of a chalk upland which, presumably in early 

 Pliocene times, occupied the place of the present sea ; the one 



Scale 



Fig. 1. — Sketch -plan (by liev. E. Hill) of the "westerly chalk hluff" at 

 Trimingham (see Plate XXII in the volume for last year). 

 The broken line indicates the boundary of chalk or clay in April, 1905 ; the 

 continuous one that observed on almost the same day in the present year. 

 A, E, C correspond with the masses bearing these letters on the above-named 

 Plate, the first being the ' contorted ' one, the condition of which at the latter 

 date is shown in Fig. 2. The plan, Mr. Hill wishes me to say, does not 

 pretend to minute accuracy. 



which made it lying to the south-west and west. Mr. Brydone 

 states that the uppermost part of the chalk (about two feet) visible 

 at the headland differed from that below, lithologically in its grey 

 colour, more crumbly condition, and apparently horizontal stratifica- 

 tion, and palgeontologically in several respects, notably the absence 

 of Ostrea lunata ; that this grey chalk formed an apparent connection 

 with the chalk mass, then only recently disclosed (C), and, when 



' This sentence was written in May; see Geol. Mag,, July, p. 335. 



- The ' southern ' chalk masses are mentioned only once in that paper, in a few 

 lines at the end of p. 400 and beginning of p. 401. I shall again briefly refer to 

 them in the present paper. 



^ Ann. Nat. Hist., sec. v, vol. vi, p. 305. 



DECADE v. — VOL. III. — NO. IX. 26 



